The present invention relates to a device for transporting liquids, such as insect repellant, fragrances, or insecticides, from a reservoir to a surface exposed to the ambient air.
Devices that release vapors into the ambient air are well-known in the art. Generally, the purpose of these devices is to deodorize or disinfect the ambient air, or to distribute toxins into the air to kill or repel unwanted pests, such as mosquitoes.
To achieve the goal of dispensing vapors into the air, a number of methods has been employed. For example, aerosol containers have been used to eject vapors into the air upon the activation of a trigger by the user. Other methods, however, utilize the evaporative properties of liquids, or other vaporizable materials, to cause vapors with desired properties to be distributed into the ambient air. One such evaporative method utilizes a wick to deliver a vaporizable liquid from a reservoir to a surface exposed to the ambient air. As the liquid reaches the exposed surface, the liquid is vaporized and dispersed into the ambient air. The exposed surface may be either the surface of the wick or the surface of another body in fluid communication with the wick.
An example of a wick-based, controlled release device is disclosed in U.S. Pat. No. 2,277,377. This patent discloses a device that comprises a cotton wick surrounded by a sheath made of bentonite, a clay-like substance. The device is inserted into a reservoir to lift liquid from the reservoir to the surface of the bentonite sheath. Another method for transporting a liquid to a surface is described in U.S. Pat. No. 4,913,350. This patent discloses an air-freshening device that uses an external, non-porous capillary member to transport the liquid from a reservoir to a surface exposed to the ambient air.
Difficulties can arise, however, when the liquid that is to be transported consists of a mixture of water-based liquids and oil-based liquids. In particular, the oil-based liquids are usually embedded in the water-based liquids and, therefore, the oil-based liquids do not easily reach the exposed surface. Therefore, there is a need for an improved method for transporting water-based and oil-based liquids from a reservoir to a surface.
Although not in the field of fragrance or insecticide release, several techniques have been used to separate oil-based and water-based liquids from one another. For example, U.S. Pat. No. 5,006,264 relates to a method for siphoning water and oil from a mixture of the two. Also, British Patent Specification No. 628,464 discloses that hydrophobic and hydrophilic porous members can be used to separate a mixture of oil-based liquids and water-based liquids. Both of these patents disclose methods of separating oil and water. However, they do not disclose transporting two different types of liquids (i.e., water-based and oil-based) to a surface so that they are in close proximity to one another.